Continuous sterile water supply system



March 25,l 1947. E. ROTHWELL CONTINUOUS STERILE WATER SUPPLY SYSTEM Filed Oct. 3l, 1944' Patented Mar. 25, `1947 CGNTINUOUS STERILE WATER SUPPLY SYSTEM Ernest Rothwell, Rochdale, England, assignor to Chas. F. Thackray Limited, Leeds, England, a

British company Application October 31, 1944, Serial No. 561,292 In Great Britain November 23, 1943 4 Claims.

This invention has reference to improvements in continuous sterile water supply systems particularly adapted for use in hospitals and establishments Where it is of the utmost importance that a sterile Water supply should be available which is not subjected to the possibility of infection or pollution from bacteria or other material,

The primary object of the invention is to utilise condensed steam from suitable sources for example from hospital sterilizers and pressure steam mains, etc. Such condensate, being absolutely germ free, thus avoids the possibility of any infection from the use of the distilled Water so formed and which can be utilised for various purposes such as in a hospital operation theatre, where a continuous supply o1" boiling, hot, warm and cool sterile distilled water can be made available at any time in regular and dependable quam tities for various purposes.

The invention consists of a continuous sterile distilled water supply system comprising a collection tank for condensed steam to form a sterile distilled Water supply, a pair of interconnected circulating subsidiary tanks, one of which has direct connection to the collection tank, a steam supply to the collection tank and to the circulating system for initial and subsequent sterilization of the apparatus, a suitable steam pump or pumps for transferring the sterile distilled Water from the collection tank to the subsidiary tanks, a steam heated calorier for re-heating, where necessary, the Water in the circulating system to any desired temperature, means for mixing the Water drawn from both of the subsidiary tanks to deliver Warm water at a predetermined temperature, outlet valves to admit of the separate draw on" of the contents oi the subsidiary tanks, also subordinate means for reheating the water drawn from any individual draw off valve by means of an electrically operated automatically controlled heater, also means for automatically cooling the heated condensate to provide a cold sterile distilled water supply and a condenser to utilise the cooling Water so used to provide an additional source of sterile distilled water.

As a means of appreciating one manner of `from tank n to tank m.

carrying the present invention into practice there is appended to this specication a diagrammatic drawing showing a schematic lay-out of a plant, but it will be obvious that various modifications and changes may be made in the lay-out and details of the plant Without departing from the scope of the present invention `as determined by the claims appended to this speciiication.

Referring now more particularly to the accompanying diagram, there is provided a means of supply of condensed steam say from the condon sate mains of ste-am sterilizers or other suitable sources which is connected by a pipe line a incorporating a filter b and a check valve c to an en closed collection tank d into which the condensed steam continually-discharges. This tank is pro vided With a pressure relief valve c1. This collecltion tank d which would be of substantial capacity, forms a reservoir of sterile distilled water for circulation throughout the system, the collection tank being provided with a, drain cock e for emptying the tank when desired for repairs, etc. and anoverow valvev f, the outlet Wherefrom is Water sealed at f1 in the overliow pipe. The overflow can be arranged to return the excess Water to the hot Well in the boiler house, without any contact of the collection tanks contents with atmospheric conditions in certain circumstances through a pipe f2.

From the collection tank d there passes a valve controlled supply pipe 7' to a steam pump or pumps k and k1 whereby the heated sterile dis tilled water is transferred, by the operation of the pump lc or k1 through the steam heated calorier Z by means of a main supply pipe jl, to one of a pair of subsidiary tanks 'm and n arranged at a higher level than the collection tank d so as to provide by gravity a head of Water to be supplied to various parts of the establishment, the flow of Water through pipe il to tank m being indicated by arrow. To the pumps k and k1 there is con nected a steam supply pipe o for their operation, suitably valve controlled for operational or isolation purposes, the exhaust steam from these pumps being discharged through pipe p into the collection tank d, on top of which is provided a Water sealed steam vent f3 to discharge its contents into the funnel iixed at the top of the overiiow f2 'The subsidiary tank m is interconnected With the other subsidiary tank n by means of a Iconnecting pipe q which terminates near the top of both tanks to ensure a non-return of cooled water A balancing pipe r is also provided to enable tank n to ll from tank m.

In addition, an overflow pipe s, with its outlet near the top of tank m, is also provided to discharge excess Water back to collection tank d. Both tanks m and n are provided with drain ycocks t and t1.

Tank n will have a Water cooling coil u to provide means of cooling itscontents to a predetermined temperature. Cold Water is admitted automatically to coil u as required, control being effected by means of a thermostatic device.

The cooling Water from coil u is utilised to provide a means of cooling the steam coil in the condenser n before discharging to hot Well or drain. By this means, an additiona1 source of sterile distilled water is formed in condenser o and automatically discharged by suitable trap through pipe w to collection tank d. Means are also provided to discharge al1 condensate from steam traps in the system to the collection tank d, as for example from traps :121, and x2.

For the distribution ,of hot sterile distilled water round the establishment, branch pipes are taken at any desired point from supply pipe 71 to suitable draw 01T taps. In the case of cooled Water, a pipe i2 is led round the establishment from tank n and branch pipes connected from it to suitable draw ofi' taps for cooled sterile distilled water Wherever required. In those cases Where Warm sterile distilled Water is required, as for example in the scrub up room of a hospital operation theatre, branch pipes from hot and cold pipes 71 and 92 may be connected to a thermostatically operated mixing valve y, the outlet of which will give Water at the temperature required. Where it is necessary to provide boiling sterile distilled Water, a pressure operated Velectric heater a may be installed at suitable points and connected from pipe 1'1 to suitable draw off taps.

By the use of a self-contained water supply system from condensed steam as hereinbefore described all risk of infection or pollution of the water supply is avoidedand a continuous supply of sterile distilled water at different. temperatures is available at all times. I

I claim:

1. A continuoussterile water supply system, comprising, in combination, a collection tank, means for supplying sterile Water to the collection tank, a primary storage tank at a higher elevation than the collection tank, a distribution line from which Water is drawn for use at a lower elevation than the primary storage tank, means for pumping Water from the collection tank through said distribution line to the primary storage tank, a secondary storage tank, an overow from the primary storage tank to the secondary storage tank, a second distribution line through which Water iioWs by gravity from the secondary storage tank, and means for heating the water initially entering one of said distribution lines.

2. A continuous sterile water supply system, comprising, in combination, a collection tank, means for supplying sterile water to the collection tank, ahot water tank at a higher elevation than the collection tank, a water heater, a hot water distribution line from which hot Water is drawn for use at a lower elevation than the hot Water tank, means for pumping Water from the collection tank through the hot Water heater and then through the hot water distribution line to the hot Water tank, a cold Water tank, an overflow line from the hot Water tank to the cold Water tank, and a cold water distribution line through which Water iiows by gravity from the cold Water tank.

3. A continuous sterile water supply system as claimed in claim 1, comprising an overflow line to the collection tank that leads from the primary storage tank at a higher level than the overow line to the secondary storage tank.

4. A continuous sterile Water supply system as claimed in claim 2, comprising an air line connecting the top of the hot Water tank to the top of the cold Water tank, and means for cooling the Water in the cold water tank.

ERNEST ROTHWELL.

REFERENCES CITED The following references are of record in the i'lle of this patent:

UNITED STATES PATENTS Number Name Date 821,187 Peters May 22, 1906 984,552 Gambati Feb. 2l, 1911 1,246,146 Noble Nov. 13, 1917 

